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Between 1993 and 1998, a randomized trial at MDACC was conducted to assess the effectiveness of two radiotherapy doses, 70 Gy versus 78 Gy, in preventing biochemical and/or clinical relapse of prostate cancer.

Materials and Methods

Of 301 evaluable patients, 150 were randomized to receive 70 Gy and 151 to 78 Gy

A significant improvement in FFF was achieved by delivering an additional 8 Gy of radiotherapy in patients considered at intermediate-to-high risk of recurrence

Rectal side effects were significantly more frequent in those receiving the additional 8 Gy

Newer radiotherapy techniques that facilitate minimizing the rectal volume that receives > 70 Gy to less than 25% should help reducing the rectal complications

Clinical/Scientific Implications

Dose escalation with radiation therapy has become extremely popular in the prostate cancer area despite limited long-term data. This study shows some benefit in regards to FFF in patients with a PSA > 10 ng/ml. There was no overall survival benefit. The authors used the FFF endpoint as opposed to strictly a PSA biochemical failure endpoint. It was not clear how many failed clinically but not biochemically. The current trend is to treat all early stage prostate cancer patients with higher doses then were traditionally delivered a few years ago, but this study does not support that practice for patients with a PSA < 10 ng/ml. There are some important technical issues in this study. The doses mentioned in this study are calculated at the isocenter of the radiation field. Doses at the periphery of the gland were ~5% lower. The group receiving 70 Gy was treated entirely with a 4-field technique while the group receiving 78 Gy was treated with a 4-field technique up to 46 Gy and then with a 3D-conformal technique with tight posterior/superior margins for the remainder 32 Gy. It is unknown how the outcome achieved by new technologies that use tighter margins (like IMRT) to reduce rectal complications will be affected by factors like organ motion, beam penumbra, and daily set-up variations

Oct 4, 2010 - Men with advanced prostate cancer that has resisted prior chemotherapy with docetaxel survive a median 2.4 months longer if they take cabazitaxel instead of mitoxantrone, according to the results of a phase III trial published in the Oct. 2, cancer-themed issue of The Lancet.